用sbt編譯spring的問題

最近在用sbt開發springmvc應用，其實主要是爲了能用scala，由於對spring還不是很熟，資料裏都是用Java寫的，因此暫時倒尚未用scala寫。今天配置aop，大概代碼以下：

@Around(value = "execution(* get(..)) && args(bookId, session) && @annotation(m)")
	public Object doGetBook(ProceedingJoinPoint pjp, long bookId, HttpSession session, MonitorPerformance m)
			throws Throwable {}

@RequestMapping(value = "/1", method = RequestMethod.GET)
	@ResponseBody
	@MonitorPerformance(2)
	public String get(@RequestParam(value = "bookId", required = false) long bookId, HttpSession session) {}

不過container:restart的時候老是報異常：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'config': BeanPostProcessor before instantiation of bean failed; nested exception is org.springframework.aop.aspectj.AspectJAdviceParameterNameDiscoverer$AmbiguousBindingException: Found 2 candidate variable names but only one candidate binding slot when matching primitive args
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:471)
	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:700)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:760)

覺得是不能用long，因而改成Long，還有異常以下：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'config': BeanPostProcessor before instantiation of bean failed; nested exception is org.springframework.aop.aspectj.AspectJAdviceParameterNameDiscoverer$AmbiguousBindingException: Still 2 unbound args at this(),target(),args() binding stage, with no way to determine between them
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:471)
	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:700)

可是發現，此次在eclipse裏面是能夠單獨跑起來的，可是用sbt編譯事後就是不行！後來想到是否是由於sbt編譯沒有保留debug信息的緣故，由於eclipse默認是保留的，因而把eclipse的去掉，果真不行！而後在sbt裏面加上保留debug信息的配置：

javacOptions ++= Seq("-g")

可是其實不是在任何環境下均可以保留debug信息的，難道spring沒有提供這種場景下的使用機會？！確定不對！google以後發現，原來是能夠@Around(@Before, @After等也能夠)中配置argNames的。以下：

@Around(value = "execution(* get(..)) && args(bookId, session) && @annotation(m)", argNames="pjp, bookId, session, m")
	public Object doGetBook(ProceedingJoinPoint pjp, Long bookId, HttpSession session, MonitorPerformance m)
			throws Throwable {}

這樣就能夠把sbt裏javaOptions去掉！而後訪問的時候又異常！

nested exception is java.lang.IllegalStateException: No parameter name specified for argument of type [java.lang.Long], and no parameter name information found in class file either

有了剛剛的經驗，很容易知道，應該仍是沒有debug信息的問題。spring須要指定@RequestParam，能夠這樣配置：

@RequestMapping(value = "/1", method = RequestMethod.GET)
	@ResponseBody
	@MonitorPerformance(2)
	public String get(@RequestParam(value = "bookId", required = false) Long bookId, HttpSession session) {}

required默認爲true，不修改的話，不帶參數會報錯的，爲了測試簡單我修改成false。

總結就是配置的時候儘可能全面，不要依賴編譯時候會有debug信息。由於method的參數，若是沒有保留debug信息，是不知道名字的。對於class類型的話，到能夠經過Class信息判斷，可是對於primitive以及對於的wrapper類，還有String，都是不行的。